Infections by Gram-positive bacteria have been of growing medical concern due to an increased incidence of infection observed in health care institutions world-wide. Among the most problematic Gram-positive bacteria with regard to human pathology are Staphylococcal species, Enterococcal species, and Streptococcal species, among others. Even more troubling is the increasing trend toward antibiotic resistance shown by these and other Gram-positive bacteria, such as, for example, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Accordingly, there remains a need for compositions and methods to prevent and treat Gram-positive bacterial infections.